How did Jonas’s relationship with his parents and friends change after he received his Life Assignment in The Giver?
Until Jonas received his assignment, he had a normal parent / son relationship. He believed everything they told him out of both deference to their authority, and trust in the community's values and norms. Following his designation as Receiver and receipt of the paper outlining his duties and rights, Jonas realizes that if he is allowed to lie, perhaps his parents are too. If this is the case, then how can he possibly know what is the truth. How can he trust a word his parents say? How can he trust in the rules that govern his life? If his parents are allowed to lie, how can he ask a questions and trust the response? This revelation attacks the very foundation of his relationship with his parents.
His friends live in a very black and white world (literally) governed by the rules of the society. Jonas, upon receipt of his position, is exposed to the incredible and unbelievable truths of his society. How can he possibly explain to his friends what 'giving' and 'receiving' entails? Even if he were permitted to. His relationships change from dynamic and stimulating to superficial and restrictive. He can not trust anyone other than The Giver, since no one knows or understands the fragile infrastructure of their society.